Luo Ji, Yang Zhong Qin, Xue Zeng Quan, Liu Wei Min, Wu Jin Lei
Surface Physics Laboratory, Fudan University, Shanghai 200433, China.
J Chem Phys. 2006 Sep 7;125(9):094702. doi: 10.1063/1.2345059.
It is shown from Kohn-Sham (KS) density-functional theory that in a large molecular system, the Coulomb potential, molecular electrostatic potential, and KS effective potential may exhibit an approximately homogeneous variation in space, in response to a small change of the electron number. The homogeneous variation of potentials underlies the constant interaction (CI) model of quantum dots (QDs) and is related to the delocalization and invariance of KS orbitals, the identical shift of KS levels, and a natural definition of the QD capacitance. Calculation results of a fullerene C60 and a single-walled carbon nanotube are presented. Although the homogeneity of the potential variation is not perfect, it seems to lead to fairly good approximation of the CI model to the addition energy spectra of these systems.
从科恩-沙姆（KS）密度泛函理论可以看出，在一个大分子系统中，库仑势、分子静电势和KS有效势可能会随着电子数的微小变化而在空间中呈现出近似均匀的变化。势的均匀变化是量子点（QD）恒定相互作用（CI）模型的基础，并且与KS轨道的离域化和不变性、KS能级的相同位移以及量子点电容的自然定义有关。给出了富勒烯C60和单壁碳纳米管的计算结果。尽管势变化的均匀性并不完美，但它似乎能使CI模型对这些系统的添加能谱给出相当好的近似。
